Scanning force microscopy investigations of biopolymers

Scanning force microscopy (SFM) has opened doors to fundamentally new kinds of biopolymer characterization. Three-dimensional structural imaging down to the molecular scale in important fluid environments is now possible. Dynamic phenomena such as protein crystal growth, and the response to nanomanipulations by the SFM probe, have been imaged in real time. Biologically specific adhesion measurements at the level of single bonds have been reported, and two-dimensional adhesion images obtained. Viscoelastic and frictional behavior in condensed biopolymer systems have been probed down to the ≈10 nm scale. This article provides an overview of these novel SFM capabilities, as well as state-of-the-art structural imaging methodologies.